Concern has been raised about the "dramatic lack of data" available documenting the quality of advanced cancer care. Our previous study identified processes of overuse of chemotherapy, underuse of hospice services, and outcomes of frequent emergency room visits, hospitalizations, and intensive care unit (ICU) admissions (possibly indicating misuse of aggressive interventions) near the end of life as potential quality indicators meriting further evaluation. Assessment of their statistical properties indicates acceptable accuracy, reliability, and variation to serve as quality indicators. Implementation in Medicare claims for older patients with terminal lung, breast, colorectal and other gastrointestinal cancers found steadily increasing use of chemotherapy very near death over a four-year span in the mid-1990s, a trend that was also associated with a rise in potentially negative outcomes such as increased emergency room visits and ICU admissions and delayed hospice admission. Moreover, these were more likely to be experienced by African-American patients and patients living in areas with less hospice services. The current proposal would further evaluate these proposed quality-of-care indicators by 1) expanding the analysis of determinants of aggressive practice to patients of different ages, diseases, and insurance types; 2) evaluating the effect of aggressive care given near the end of life on outcomes such as survival, complications, and cost; and 3) further evaluating the construct that aggressive care may be an indicator of poor quality care. The goal is to develop measures of potential overly aggressive cancer care near the end of life that can be used as quality of care indicators to identify providers (institutions, practices, or physicians) that consistently administer such care to a high proportion of patients. Once identified, reasons could be sought and appropriate interventions, such as increasing access to palliative services, could be instituted.